The present invention relates to systems and methods for mechanically supporting and electrically coupling arc tubes in high intensity discharge (“HID”) lamps such as metal halide lamps. More particularly, the invention relates to such systems and methods which provide mechanical support and electrical coupling of the arc tube in an HID lamp with few or no welds.
HID lamps such as metal halide lamps have found widespread acceptance in lighting large outdoor and indoor areas such as athletic stadiums, gymnasiums, warehouses, parking facilities, and the like, because of the relatively high efficiency, compact size, and low maintenance of HID lamps when compared to other lamp types. A typical HID lamp includes an arc tube which is mechanically supported within a light-transmissive outer lamp envelope. The arc tube includes two or more electrical leads which are each electrically coupled to a source of electrical power exterior of the outer lamp envelope.
In such a lamp, the mounting structure which provides mechanical support and electrical coupling for the arc tube within the outer lamp envelope includes one or more metal components which are welded for mechanical and electrical integrity. In the fabrication of such lamps, the practice of welding such components, unless automated, is labor intensive which adds expense to the fabrication process. Further, the welding of various lamp components requires numerous weld schedules for the components which may comprise different materials and geometries. Still further, the welding electrodes require a significant amount of maintenance to achieve an optimum weld. Thus the elimination of welds in the mounting structure for the arc tube is desirable to reduce the time and expense required to fabricate such lamps.
Another disadvantage of the typical HID lamp mounting structure having welds to maintain the mechanical and electrical integrity of the structure results from the susceptibility of the one or more welds in such lamps to mechanical failure during shipping of the lamps. The welds provide a relatively strong mechanical coupling of components when the weld is subjected to shear. However, the welds are relatively weak when subjected to a bending moment, which is the typical mode of mechanical failure in such lamps during shipping.
In the fabrication of HID lamps, it is important to properly position the arc tube within the outer lamp envelope so that the light center of the lamp is optimized. In the known methods of fabricating HID lamps, the various components of the arc tube mounting structure must be aligned manually by the production operator before being mechanically joined or fixtured with specialized tooling. Such an alignment process is time consuming if done manually and expensive if done using fixtures. Thus the elimination of the alignment process in the fabrication of HID lamps is desirable to reduce the time and expense required to fabricate such lamps.
Accordingly, it is an object of the present invention to provide a novel system and method for mechanically supporting and electrically coupling arc tubes in HID lamps which obviates the deficiencies of known systems and methods.
It is another object of the present invention to provide a novel system and method for mechanically supporting and electrically coupling arc tubes in HID lamps with few or no components which are welded for mechanical integrity.
It is yet another object of the present invention to provide a novel system and method for mechanically supporting and electrically coupling arc tubes in HID lamps with few or no components which are welded for electrical integrity.
It is still another object of the present invention to provide a novel system and method for mechanically supporting and electrically coupling arc tubes in HID lamps which is amenable to automation.
It is a further object of the present invention to provide a novel system and method for mechanically supporting and electrically coupling arc tubes in HID lamps which reduces mechanical failure during shipping of the lamp.
It is yet a further object of the present invention to provide a novel system and method for aligning the light center of an HID lamp.
These and many other objects and advantages of the present invention will be readily apparent to one skilled in the art to which the invention pertains from a perusal of the claims, the appended drawings, and the following detailed description of the preferred embodiments.